Sodium carbonate and cyanuric acid materials are added to the water of a swimming pool by compacting the materials into a tablet and placing the tablet in a swimming pool leaf skimmer.
When swimming pool water becomes too acid because of chlorination, the water has to be alkalyzed, usually with sodium carbonate powder. To stabilize chlorine in swimming pool water, cyanuric acid is added to the water in a concentration of about 100 ppm.
Extreme care needs to be taken in adding and distributing sodium carbonate powder to try to avoid exceeding the solubility of sodium carbonate in the water. If it is exceeded, a cloudy precipitate of calcium carbonate forms in the pool water. Calcium ions become concentrated in swimming pool water due to presence of calcium ions in original water and in makeup water added to compensate for pool evaporation. Calcium also can come from pool plaster. Calcium carbonate precipitate is undesirable because the precipitate does not go back into solution and the pool water remains cloudy.
Cyanuric acid is difficult to dissolve because it is only very slightly soluble. It is a weak acid and causes staining of pool plaster surfaces if undissolved. If carried undissolved into the piping system of the pool, pipes and other metal materials can be corroded.
Objectives of my invention include: to add sodium carbonate to swimming pool water in a manner preventing precipitation of calcium carbonate; to convert cyanuric acid into its mono sodium salt, which is not acid and is more soluble than cyanuric acid, before it is introduced into pool water; to add sodium carbonate or a combination of sodium carbonate and cyanuric acid to pool water; and to add these materials in the form of compacted tablets which are placed in swimming pool leaf skimmers, so that recirculating water slowly dissolves the materials in the tablets and introduces the materials gradually into the pool water.
My invention will be best understood, together with additional advantages and objectives thereof, when read with reference to the drawings.